Long low-bed trailers have always presented a problem in negotiation of sharp curves due to the tendency for the trailer to cut the corner and follow the path of least resistance in relation to the towing vehicle. Customarily, the towing vehicle or tractor is equipped with the well-known fifth wheel pivotal coupling which allows hitching up to and separation from the trailer gooseneck drawbar as well as pivoting of the gooseneck relative to the tractor horizontally or from side-to-side when negotiating turns. In order to concentrate the weight of the trailer through the gooseneck most advantageously over the rear axle assemblies of the tractor, it has always been deemed necessary to place the pivot of the trailer relative to the tractor on the strategically located fifth wheel assembly.
In recent times, the new service roads being constructed in national forests with many sharp curves have accentuated the problem and given rise to an urgent need to an improved arrangement which would enable low-bed trailers carrying heavy equipment to follow these roads satisfactorily. In the absence of a satisfactory solution to the problem, a great deal of expensive and unnecessary wear of heavy equipment, and much loss of time, has taken place where the equipment must be unloaded prior to reaching its ultimate point of use. In the case of forest fires, the fire may have advanced prohibitively far before the equipment can arrive.
Therefore, to meet the urgent needs of the art, the present invention has as its objective to provide a heavy equipment haulage caravan, including a low-bed gooseneck trailer, and a towing truck or tractor which is capable of negotiating much sharper curves than conventional caravans while still concentrating the load on the tractor at the customary point of the fifth wheel connection but without the horizontal pivoting at this point.
Instead, the pivotal connection is shifted rearwardly of the tractor and adjacent the bottom of the gooseneck drawbar, with the result that on sharp turns, the low-bed trailer will substantially follow the tracks of the towing vehicle without cutting the corner. Additionally, the relocated pivotal connection between the two components of the caravan is provided with increased strength capabilities and rigidity necessary to render the invention fully practical particularly in the handling of heavy equipment, as well as safe and reliable.
Other specific features and advantages of the invention will become apparent during the course of the following detailed description.